Contents

General information

Stringent vs. relaxed replication

Plasmid replication control is usually controlled by balancing the levels of a positive and a negative regulator of replication. For some plasmids (pMB1/colE1 replicons) the positive regulator is an RNA and in others (e.g. pSC101) it is a protein. Plasmids with a protein positive regulator will not replicate in the abscence of protein production - stringent control (although not the same as the stringent response due to a shortage of loaded tRNAs). Plasmids with an RNA positive regulator will continue to replicate in the abscence of protein production. This is termed relaxed control. High yields of plasmid may be obtained by halting protein production (via chloroamphenicol) when the culture reaches a high density and then continuing incubation for a number of hours. This might be of practical relevance when prepping the 1 and 3 series of Synthetic Biology plasmids.--BC 19:05, 3 Sep 2005 (EDT)

Online Vector Databases

You can often find vector information at NCBI, either directly or in their list of vectors screened for contamination of new sequence at Vecscreen.

VectorDB contains information about many common vectors, including yeast vectors.

Addgene's Vector DB contains most of the information from Stanford's VectorDB, plus more vector information they have curated from commercial websites and added through our plasmid curation efforts. (However, it seems to be rather sparse when it comes to Escherichia coli vectors.) Note that Addgene is a a non-profit plasmid repository where scientists can archive and share their plasmids. They encourage and invite labs to deposit plasmids at Addgene. They help you with data submission and all tech transfer issues. Plasmids can be requested from Addgene for a fee to cover expenses.